AI Model Release Tracker - Timeline of Major AI Models from 2022-2026

Home/Compare/Claude Opus 4.5 vs Grok 4.1 Fast

Claude Opus 4.5 vs Grok 4.1 Fast

2 vs 0 benchmarks won

Anthropic
Claude Opus 4.5
xAI
Grok 4.1 Fast
Overview
CompanyAnthropicxAI
Release dateNov 24 2025Nov 19 2025
Model type
Open sourceNoNo
Specifications
Parameters
Context window
Benchmarks
Science reasoning
GPQA Diamond
87%
Software engineering
SWE-Bench Verified
80.9%
Multimodal understanding
MMMU
Timeline
Release gapGrok 4.1 Fast shipped 5 days before Claude Opus 4.5

Which is better: Claude Opus 4.5 or Grok 4.1 Fast?

Claude Opus 4.5 leads Grok 4.1 Fast on 2 of the tracked benchmarks (GPQA Diamond, SWE-Bench Verified, MMMU). Grok 4.1 Fast shipped 5 days before Claude Opus 4.5, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

Direct benchmark comparisons are unavailable — at least one of these models has not published scores on GPQA Diamond, SWE-Bench Verified, or MMMU.

Frequently asked questions

When was Claude Opus 4.5 released?
Claude Opus 4.5 was released by Anthropic on Nov 24 2025.
When was Grok 4.1 Fast released?
Grok 4.1 Fast was released by xAI on Nov 19 2025.

Other comparisons